High level are now selling two sizes of coreless motors, made to our own specification and suitable for use in 4mm scale locos. We may expand this range with additional sizes for larger locos...

There’s some talk about some coreless motors not behaving very well with certain controllers, in particular, early feedback types.

I would be interested to know your experiences with RG4s, or any other types of coreless motors, and which specific controllers they seem to have a problem, or, run well with. Hopefully, I’ll be able to create a database for the website whihc will assist with motor choice.

High Level Kits wrote:There’s some talk about some coreless motors not behaving very well with certain controllers, in particular, early feedback types.

I recall that the problem was with controllers that used a low frequency pwm, particularly when starting, where the low mass of the windings of a coreless motor allowed the armature to stop between pulses. This meant that the windings took a starting surge of current many times a second, to the detriment of brush survival. I think it was Stewart Hine who identified the issue.

A solution was to use pure DC controlled by resistance like the old H&M type controllers, or if possible, set your controller to 'smooth' or high frequency pwm. This should be possible with the cvs available with DCC chips, I wouldn't know.

It is certainly possible with the DT radio receivers, though they come with a default high frequency anyway, typically 16KHz, which will do no harm to a coreless motor.

I wonder, how many modellers on here know what their controller is doing?

I have just converted an 00 Works LSWR D15 4-4-0 to EM, and first of all tested it on the reduced feedback AMR handheld controller I use in the workshop. It ran appallingly so I started to wonder what I had taken on - until I read the instructions (!) and found out that it was fitted with a coreless motor. I switched to a Modelex handheld and it ran like a dream, wonderful start and it just glided along. Further investigation revealed a small motor and a very nice set of straight cut gears. Remembering the infamous Portescap whine, I was also pleased that it was virtually silent.

I have another D15 to do next week, and that will be used on DCC (not by me, I just put the wiring in under guidance!) so I might be able to report how that pans out. I’ll also have a look at the motor to identify what exactly it is.

I think it was Roy Jackson who first recommended Modelex to me, and I will be investing in another sometime. Certainly it gives good results with most of the other engines I have had here over the years. Sometimes the AMR gives a slightly better start, but the Modelex is quieter.

The odd thing is that I have, years ago, built several engines with a 1616 Portescap, and they all ran well on the AMR. Come to that, they weren’t that fussy about controllers.

Chris, I think you can safely add a Gaugemaster handheld (the cream, non feedback one, definitely not the black feedback one) to the yes list. I might have one, not sure. I’ll test the D15 on a handheld Pentroller later. I guess a Pictroller would also be OK, but no experience here.

High Level Kits wrote:There’s some talk about some coreless motors not behaving very well with certain controllers, in particular, early feedback types.

I recall that the problem was with controllers that used a low frequency pwm, particularly when starting, where the low mass of the windings of a coreless motor allowed the armature to stop between pulses. This meant that the windings took a starting surge of current many times a second, to the detriment of brush survival. I think it was Stewart Hine who identified the issue. ...

The problem was with the ECM controlers (Compspeed) which used relatively low frequency pulses. These aren't now available so its only those of us which still have them about who need worry about it.

It has been pointed out to me that many of these controllers we have all had for donkeys’ years, and current examples may not have the same characteristics even though the case may be the same. So it might be best to check out current examples of the appropriate ones - my Modelex is about seven years old and the latest Gaugemaster about two.

The same might apply to motors; the ones you have may not perform the same as the one in the engine I tested. I’ve included a picture of that motor; as you will see there are no markings on it but it measures 19.5mm x 12mm.

There were three ancient controllers (Scalespeed, Digitol 4 & H&M Powermaster) that I didn’t test because they were so old and not of current interest.

Chris, all the ones that were ok are, as far as I know, non - feedback. Or at least have a circuit that doesn’t give a coreless motor the jitters. The two Pentrollers have a selector switch for 1219 or 1616/24 motors, and another setting for ‘iron cored’ motors, as Stewart Hine called them, and I think that setting had feedback of a sort.

The AMR & black Gaugemaster controllers have feedback.

The only two currently available are the Modelex and cream model W Gaugemaster. There is also the Pictroller, a successor to the Pentroller, but I tested one a long time ago and wasn’t impressed with the control it gave. Nothing to do with coreless motors or feedback, just not impressed.

ChrisMy best controller for coreless motors is a Kent Panel Controls model KFS. This can be operated with feedback switch on, or switched off for coreless motors. I have locos fitted with the various sizes of motors previously available, including the 1219.

Unfortunately these controllers are not available any more - I understand that the owner of Kent Panel Controls died in a motorway accident.

I also use the non-feedback (cream) Gaugemaster mentioned by Philip, but prefer the Kent Panel Controls model.

Thanks for all the input up to now. I'm not chipping in much because I'm still gathering info.

One question on my mind is ‘are there any differnces between the way various makes/models coreless motors react to the controllers. It would be convenient be able to say, ‘if it works with an RG4 then you should be OK with a High Level Coreless but is this the case?...

Anyone who’s bought one of our coreless, 1219 or 1320 please pipe up and say how it runs, and what you’re using it with?...

IANATEXTON wrote:ChrisMy best controller for coreless motors is a Kent Panel Controls model KFS. This can be operated with feedback switch on, or switched off for coreless motors. I have locos fitted with the various sizes of motors previously available, including the 1219.

Unfortunately these controllers are not available any more - I understand that the owner of Kent Panel Controls died in a motorway accident.

I also use the non-feedback (cream) Gaugemaster mentioned by Philip, but prefer the Kent Panel Controls model.

Kind regardsIan

Ian, where is the on/off switch for the feeedback on your Kent controller?